中文摘要：

目的：苯并（a）芘（benzo（a）pyrene,Ba P）被证实是对生殖有不良影响的雌激素类似物,研究发现苯并（a）芘影响胚胎着床,本研究检测Ba P对早孕小鼠子宫中Wnt信号通路的影响,以探讨其干扰胚胎着床的机制。方法：将成年雌雄昆明鼠进行交配,次日见阴栓记为妊娠第1天（D1）。将孕鼠随机分为玉米油对照组（n=45）和Ba P处理组（n=45）,玉米油对照组从妊娠第1天开始给予玉米油灌胃,Ba P处理组则给予0.2 mg/（kg·d）的Ba P进行灌胃,直至妊娠的第4、5、6天（D4、D5、D6）分别处死,收取子宫材料,计数着床点数目,采用荧光定量PCR,免疫组化法,Western blot分别检测所收集子宫内膜材料中Wnt信号通路相关基因表达情况。结果：苯并（a）芘染毒后,引起胚胎着床数下降,差异具有统计学意义（P=0.000）;荧光定量PCR显示Wnt7a m RNA水平在Ba P组较对照组表达下降,差异具有统计学意义（P=0.000）;而β-catenin m RNA在Ba P组水平升高,差异具有统计学意义（P=0.002、P=0.003、P=0.011）;Western blot和免疫组化也均显示Ba P染毒后Wnt7a的表达下降,β-catenin的表达有所上升。结论：苯并（a）芘可能通过干扰Wnt7a、β-catenin的表达影响小鼠胚胎着床。

英文摘要：

Objective：To explore the effect of benzo（a）pyrene（Ba P）on Wnt signaling in mice uteri during early pregnancy. Methods：Adult female and male Kunming mice were mated to produce pregnancy. The pregnant mice were divided into two groups ：control group（n=45）;Ba P-treated group（n=45）,and then received corn oil and 0.2 mg/（kg·d）Ba P respectively from D1. The uteri were collected on pregnant 4 to 6 days respectively and the implantation numbers were counted. Real-time PCR（q RT-PCR）,Western blot and immunohistochemistry（IHC）were used to detect the gene expression of Wnt signaling pathway. Results：The implantation numbers were reduced in Ba P-treated group than in control group（P=0.000）. The results of RT-PCR revealed down-regulated of m RNA levels of Wnt7 a in Ba P-treated group（P=0.000）,whereas the expression of β-catenin was elevated in this group（P=0.002,P=0.003,P=0.011）. Western blot and IHC also showed the up-regulated expression of β-catenin,and the reduced expression of Wnt7 a in Ba Ptreated group. Conclusion ：Ba P can lead to the aberrant expression of Wnt7 a and β-catenin,which might interfere embryo implantation.